Steam-boiler and other furnace.



P. JONES.

STEAM BOILER AND OTHER FURNACE.

APPLIOATION FILED JAN. 6, 1912.

2 SHEETS-SHEET l.

Patented Mal; 10

P. JONES.

STEAM BOILER AND OTHER FURNACE.

APPLIOATION FILED JAN.6,1912. 1 089 476 Patented Mar. 10, 191 i 2 SHEETS-SHEBT 2.

W1 gesss? PETER JONES,

OF WIGAN, ENG-LAND.

STEAM-BOILER AND OTHER FURNACE.

Specification of Letters Patent.

Patented Mar. 10, 1914.

Application filed January 6, 1912. Serial No. 669 .840.

To all whom it may concern Be it known that I, PETER Jonas, subject of the King of Great Britain, residing at Wigan, in the county of Lancaster, in the Kingdom of England, have invented certain new and useful Improvements in Steam- Boiler and other Furnaces, of which the following is a specification.

This invention relates to apparatus or appliances for securing more perfect combustion of the fuel and the prevention of smoke in steam boiler and other furnaces, such apparatus being of the type wherein the unconsumed gases passing away from the rear end of the furnace, are injected back into the furnace, together with a supply of air, so that the mixture of said combustible gases and air will be consumed by the fire.

More specifically the invention consists in certain improved arrangement of parts for effecting the desired result, and to thls end the ash pit at the back end of the grate is closed by a partition wall, and passing forwardly underneath the grate at each side, I place a large pipe or duct, which forms a communication from the smoke chamber and the rear of the furnace, to the front of the furnace. Through these ducts the escaping gases from the furnace are delivered into the fire at the front end in close proximity to air inlet orifices, so that the commingled air and combustion gases are directed into the fire. Furthermore, in order to direct the escaping combustible gases toward the forwardly extending ducts, I make the fire grate in such manner as to cause the escaping gases to be delivered to some extent 1n two streams toward the respective ducts. For this purpose the grate is made of the convex type, but in such manner as to attain its maximum convexity at the rear, while toward the front the convexity gradually decreases to zero.

The invention will be understood from the following description, references being had to the accompanying drawings, in which Figure 1 is a longitudinal section through a furnace tube and boiler on line w w of Fig. 3; Fig. 2, a sectional plan view of the furnace grate and smoke chamber; Fig. 3, a part front view and part vertical section; Fig. 4, a front view of the furnace door frame; Fig. 5, a perspective view of fur nace and its appurtenances separated from the furnace tube. Fig. 6 is a vertical section through the furnace tube looking toward the boiler front.

The rear of the ashpit G below the sloping convex grate A is hermetically closed by a downwardly extending partition H shaped to fit the space below the grate, but in order that this shall not obscure a clear view of the smoke chamber I at the rear of the furnace, or obstruct the removal of ashes, I provide this partition with a hinged door I. The opening and closing of this door is controlled from the outside by rods or chains, and during normal working this door is closed.

Underneath the grate at each side I place a large pipe J which forms a communica. tion from the smoke chamber I at the rear of the furnace, to the furnace at the front. The rear ends of these pipes are secured in the partition H, while the front ends are secured to T piece unions K, one'branch of which is closed and secured to a plate L at the front of the ashpit, while another branch. is secured to the dead-plate F, and is in communication with openings M in the said dead-plate, by which the unconsumed products of combustion passing forwardly along the pipes J are conducted to and delivered into the furnace at the front end. Or these pipes can be secured to a part made integral with the dead-plate, so that the gases passing along them will pass through the dead-plate to the fire.

The furnace front is fitted with a frame n seated on the dead-plate which frame is made with an opening N for the usual firedoor 0, and at each side of this opening, there is formed a conduit P having a floor sloping upward, through which air can flow from the front of the furnace into the fire. These conduits may be made to contract toward the rear, so that the air is compelled to pass through the contracted end thereof, by which its velocity is increased. The object of making these conduits with sloping floors is to leave space below for other conduits Q adapted to lead the smoke and products of combustion from the forwardly projecting pipes J below the grate A through the openings M in the dead plate F into the furnace above the grate A. In each forwardly projecting pipe, I place a steam-jet It adapted to direct jets of steam in a forward direction, and induce a draft along thepipes from the rear toward the front. The jets R are supplied with steam by the pipes R.

Beyond the furnace I place an ordinary bridge S rising upward from the furnace tube, and between this and the furnace grate I place a hanging bridge or midfeather arch T. This mid-feather arch, which extends downward, serves to deflect the smoke and unconsumed combustion products downward toward the entrance into the forwardly extending smoke pipes J, in which there is, by means of the steamjet-s, produced. a partial vacuum which causes the smoke to rush forwardly through the pipes to the dead-plate, and so be readmitted into the fire to pass again over the flames and incandescent fuel. To further assist in directing the smoke and unconsumed combustion products into the smoke pipes J, I cause the smoke to flow away from the furnace to some extent, in two streams. For this purpose the grate A is made of the convex type i. 6. higher at the longitudinal center line C than at the sides D, but in such manner as to have a gradually increasing convexity toward the rear. This insures that a part of the burning fuel accumulates to some depth at the sides D, and lies in direct contact with the walls of the furnace tube E, while the gradually increasing convexity of the grate toward the rear, assists in causing the combustion gases to flow away in two streams, for the purpose mentioned. The grate A attains its maximum convexity at the end, where it is required to divide the effluent gases into two streams, but this convexity gradually decreases to zero as it approaches the front of the furnace, so that at the extreme front of the furnace, where the dead plate F is, the grate is substantially the same height at the center, as at the sides.

B are the curved bearers on which the bars are laid.

The mode of action is as follows :Fuel is thrown on in the usual manner preferably at or near the front of the grate A, and the fuel is gradually worked backward. The furnace draft causes air to be drawn in through the conduit-s P at each side of the furnace door, so that it is admitted pretty uniformly over the surface of the grate, and furthermore air is admitted through the front of the ashpit and rises upward through the spaces between the bars. The grate being concave below has a larger surface than if it was made flat, and so it will keep cool much better than flat grates. The shape of the grate causes the flames to strike directly against the sides of the furnace tube E, and also against the crown, forming an intense flame bearing right against the sides and crown of the furnace. The smoke and flames passing over the rear end of the furnace are baffled by a mid-feather arch T, and

the unconsumed carbon and gases are deflected downward to some extent in two streams or currents toward the forwardly projecting smoke pipes J. Here by means of the steam jets R the greater part of the smoke is caused to enter the pipes, and to pass forwardly through these pipes below the grate to the front of the furnace where it reenters the furnace above the grate. Here the smoke mixes with the air that en.- ters through the conduits P so that the mixture of commingled air and smoke is at once consumed. The amount of smoke passing through the tubes is governed by the steam-jets R, which can be arranged either as permanent steam-jets, or regulated by means of cocks at the boiler front, so that they can be turned off when there is no smoke, or turned on every time the furnace is charged with fuel, and furthermore the amount of air entering through the front of the boiler can be regulated by hit-and-miss grid plates U.

The heavier particles of incombustible or unconsumed material which are carried away by the draft of the chimney, are stopped by the second bridge S in the smoke chamber, and are deposited in a heap V in the front of the second bridge, where they are consumed as they roll down the front of the slope, while the lighter portions are as already mentioned carried through the forwardly extending pipes J or are burnt at the very high temperature existing in the smoke chamber I, together with the unconsumed combustion products. Any accumulation of unconsumed material at the second bridge S is removed from time to time through the door I in the partition H.

In replenishing the fire, the top part of the fire at the front is pushed on to the rear part of the grate, and a fresh charge of coal thrown on the front of the fire. The airsupply at the front,through the hit-and-miss grids U, furnishes the air necessary for the combustion of the charges of fresh fuel at the front, while the air that rises up through the bars A keeps up combustion at the back as well as all along the grate.

I declare that what I claim is 1. The combination with a furnace having a dead plate and a smoke chamber, of a frame seated on the dead plate and provided with a centrally disposed opening for the fire door, an upwardly inclined air admission duct at each side thereof and smoke discharge ducts below said air admission ducts; and pipes leading from the smoke chamber and extending forwardly therefrom to the smoke discharge ducts, to discharge unconsumed products of combustion theret-hrough.

2. The combination with a furnace having a dead plate and a smoke chamber, of a frame seated on the dead plate and provided with a centrally disposed opening for the fire door, and an air admission duct at each side thereof; means adapted to conduct smoke back to the furnace from the smoke chamber and to discharge it adjacent said air admission ducts; and a grate in said furnace, said grate having an upward convexity progressively increasing toward its rear.

8. The combination with a furnace having a smoke chamber at its rear, of a grate mounted at the forward end of said furnace and having an upward convexity progressively increasing toward the rear; means adapted to feed smoke from the smoke chamber and to discharge it above the grate :13 the forward end of the furnace; and means 5 for admit-ting air at the forward end of said furnace above the grate and adjacent the point of discharge of said smoke.

In witness whereof, I have hereunto signed my name this 22 day of December 1911, in 20 the presence of two subscribing witnesses.

PETER JONES.

Witnesses G. C. DYMOND, C. BARTLETT.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). 0." 

